Electrode core, battery, battery pack, and electrical device

Abstract

The present disclosure relates to the technical field of batteries, and specifically discloses an electrode core, a battery, a battery pack, and an electrical device. The electrode core comprises a main body region and a thinned region connected to each other. The thinned region is arranged on at least one side of the main body region along a first direction, the first direction being the length direction or the width direction of the electrode core. The electrode core further comprises a first adhesive layer. The first adhesive layer is provided on at least a portion of the surface of the thinned region. The first adhesive layer comprises a plurality of sub-adhesive layers, and the plurality of sub-adhesive layers are sequentially stacked along the thickness direction of the first adhesive layer to fill and level a depression in the thinned region. In the present disclosure, the first adhesive layer is provided on the surface of the thinned region, and comprises a plurality of sub-adhesive layers sequentially stacked along the thickness direction of the first adhesive layer to fill and level a depression in the thinned region, thereby achieving perfect fitting between the first adhesive layer and the thinned region of the electrode core.

Description

Core, battery, battery pack and electrical equipment

[0001] Cross-reference to related applications

[0002] This disclosure claims priority to Chinese Patent Application No. 202422138958.9, filed with the China National Intellectual Property Administration on August 30, 2024, entitled "Core, Battery, Battery Pack and Electrical Equipment", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure belongs to the field of battery technology, specifically relating to an electrode core, a battery, a battery pack, and an electrical device. Background Technology

[0004] The core of a lithium-ion battery mainly includes a positive electrode, a negative electrode, and a separator. To avoid the edge of the coating slurry from flowing during coating and the phenomenon of excessively thick edges due to the surface tension of the slurry, a "core thinning zone" is required during coating of the positive and negative electrodes, as shown in Figure 1.

[0005] As the energy density of electrode cores increases, the amount of coating on the electrode sheets also increases, leading to a greater number of stacked layers and winding turns. This results in increasingly thicker edges on the electrode core, with the thickness difference between the thinned edge and the main body of the core reaching tens of micrometers to several millimeters. This phenomenon presents the following problems:

[0006] (1) When the electrode core is assembled and HI-pot test is performed, the edge has a thickness difference, which causes the edge area (i.e. the thinned area) to not be fully compressed during the short circuit test. As a result, foreign objects in the thinned area of ​​the electrode core cannot be detected, and the electrode core HI-pot test has a false negative phenomenon. Therefore, the electrode core has a safety risk in subsequent use.

[0007] (2) During the subsequent cycle of the battery, as the number of charge and discharge cycles of the electrode core increases, the electrode will continuously expand and contract under the influence of lithium ion insertion and extraction, and the thickness will also continuously increase and decrease. In this way, the distance between the electrodes will further increase in the thinning area, the lithium ion translocation polarization will increase, and the lithium ion transport resistance between the positive and negative electrodes will increase, resulting in interface deterioration (such as lithium plating, brown spots, etc.), which ultimately leads to a drop in battery capacity, affects the battery's cycle life and safety of use.

[0008] (3) Due to the thickness difference between the thinned area of ​​the active material layer and the main area, the thinned area cannot be tightly attached to the separator during the assembly of the positive electrode, negative electrode and separator into an electrode core, which makes the separator prone to wrinkles during the assembly process.

[0009] Public content

[0010] This disclosure aims to at least partially solve one of the technical problems in the related art. Therefore, the purpose of this disclosure is to provide an electrode core, a battery, a battery pack, and an electrical device. This disclosure provides a first adhesive layer on the surface of the thinned area, and the first adhesive layer includes multiple sub-adhesive layers stacked sequentially along the thickness direction of the first adhesive layer to fill the depression in the thinned area, thereby achieving a perfect fit between the first adhesive layer and the electrode core thinned area.

[0011] In one aspect of this disclosure, an electrode core is provided. According to an embodiment of this disclosure, the electrode core includes a connected body region and a thinning region, the thinning region being disposed on at least one side of the body region along a first direction, the first direction being the length direction or width direction of the electrode sheet;

[0012] The electrode core further includes a first adhesive layer disposed on at least a portion of the surface of the thinned area. The first adhesive layer includes a plurality of sub-adhesive layers, which are sequentially stacked along the thickness direction of the first adhesive layer to fill the collapse of the thinned area.

[0013] According to the electrode core of this disclosure, a first adhesive layer is formed on the surface of the thinned area. This first adhesive layer comprises multiple sub-adhesive layers stacked sequentially along its thickness direction to fill the collapse of the thinned area. This achieves complete bonding of the thinned area, avoiding missed defects in the electrode core's Hi-pot test and thus improving the electrode core's safety performance. Simultaneously, it avoids defects such as lithium plating and brown spots caused by thickness differences in the thinned area. Furthermore, it effectively prevents the electrode core from shifting, misaligning, and wrinkling during assembly. Moreover, the electrode core structure of this disclosure is simple, easy to implement, and low in cost.

[0014] In addition, the electrode core according to the above embodiments of this disclosure may also have the following additional technical features:

[0015] In some embodiments of this disclosure, the length of the sub-adhesive layer decreases along the thickness direction of the first adhesive layer away from the thinning region.

[0016] In some embodiments of this disclosure, the thicknesses of the plurality of sub-adhesive layers are 0.05 mm to 0.1 mm, respectively.

[0017] In some embodiments of this disclosure, the first adhesive layer comprises a unit adhesive layer.

[0018] In some embodiments of this disclosure, the first adhesive layer includes at least two unit adhesive layers, which are arranged sequentially along a second direction, which is the thinning direction of the thinning region, and the thickness of the at least two unit adhesive layers increases along the second direction away from the main body region.

[0019] In some embodiments of this disclosure, the thickness gradient of at least two of the unit adhesive layers increases along the second direction away from the main body region.

[0020] In some embodiments of this disclosure, the width of the thinning area is L, the first adhesive layer includes a first unit adhesive layer and a second unit adhesive layer arranged sequentially along the second direction, the first unit adhesive layer is disposed close to the main body area, and the widths of the first unit adhesive layer and the second unit adhesive layer are (1 / 3 to 2 / 3)L respectively.

[0021] In some embodiments of this disclosure, the thickness of the first unit adhesive layer is 0.05 mm to 0.15 mm, and the thickness of the second unit adhesive layer is 0.15 mm to 0.3 mm.

[0022] In some embodiments of this disclosure, the width of the thinning area is L, and the first adhesive layer includes a third unit adhesive layer, a fourth unit adhesive layer and a fifth unit adhesive layer arranged sequentially along the second direction. The third unit adhesive layer is disposed close to the main body area, and the widths of the third unit adhesive layer, the fourth unit adhesive layer and the fifth unit adhesive layer are (1 / 4 to 1 / 2)L, respectively.

[0023] In some embodiments of this disclosure, the thickness of the third unit adhesive layer is 0.05 mm to 0.1 mm, the thickness of the fourth unit adhesive layer is 0.1 mm to 0.15 mm, and the thickness of the fifth unit adhesive layer is 0.15 mm to 0.3 mm.

[0024] In some embodiments of this disclosure, adjacent unit adhesive layers are spaced apart, with a spacing of no more than 2 mm; or, adjacent unit adhesive layers are connected.

[0025] In some embodiments of this disclosure, the sum of the thickness of the first adhesive layer and the thickness of the thinned area corresponding to the first adhesive layer in the third direction is not greater than the thickness of the main body area, where the third direction is the thickness direction of the electrode core and is perpendicular to the first direction.

[0026] In some embodiments of this disclosure, the first adhesive layer is made of polyurethane or polyimide.

[0027] In some embodiments of this disclosure, the electrode core further includes a diaphragm, wherein the first adhesive layer is disposed on the surface of the diaphragm, and the distance between the first adhesive layer and the edge of the diaphragm is 3mm to 5mm.

[0028] In some embodiments of this disclosure, the electrode core further includes: an electrode tab disposed at at least one end of the electrode core along the first direction; and a second adhesive layer disposed on at least a portion of the surface of the electrode tab near the thinning region, wherein the second adhesive layer is connected to the first adhesive layer.

[0029] In some embodiments of this disclosure, the distance between the second adhesive layer and the welding edge on the electrode tab is 3mm to 5mm.

[0030] In some embodiments of this disclosure, the second adhesive layer is made of polyurethane or polyimide.

[0031] In a second aspect, this disclosure provides a battery. According to an embodiment of this disclosure, the battery includes a casing and electrode cores as described above, the electrode cores being disposed within the casing. This improves the battery's safety performance, prevents a significant drop in battery capacity, and ensures the battery's cycle life.

[0032] In a third aspect, this disclosure provides a battery pack. According to embodiments of this disclosure, an electrical device includes the battery described in the above embodiments. This improves the safety performance of the battery pack, prevents capacity drops, and ensures the cycle life of the battery pack.

[0033] In a fourth aspect, this disclosure provides an electrical appliance. According to embodiments of this disclosure, the electrical appliance has a battery or battery pack as described in the above embodiments. Therefore, the electrical appliance possesses all the advantages of a battery, which will not be elaborated further here.

[0034] Additional aspects and advantages of this disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this disclosure. Attached Figure Description

[0035] The above and / or additional aspects and advantages of this disclosure will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0036] Figure 1 is a cross-sectional schematic diagram of a prior art battery;

[0037] Figure 2 is a schematic diagram of the structure of the electrode core according to the present disclosure;

[0038] Figure 3 is a partial schematic diagram of the electrode core according to some embodiments of this disclosure;

[0039] Figure 4 is a partial schematic diagram of the electrode core in some embodiments of this disclosure;

[0040] Figure 5 is a partial schematic diagram of the electrode core in some embodiments of this disclosure;

[0041] Figure 6 is a partial schematic diagram of the electrode core in some embodiments of this disclosure.

[0042] Reference numerals: 2000-battery, 1000-core, 100-1-positive electrode sheet, 100-2-negative electrode sheet, 200-separator, 300-1-positive electrode tab, 300-2-negative electrode tab, 400-1-positive electrode post, 400-2-negative electrode post, 1500-casing, 500-main body area, 600-thinned area, 700-first adhesive layer, 710-sub-adhesive layer, 720-unit adhesive layer, 800-second adhesive layer. Detailed Implementation

[0043] The embodiments of this disclosure are described in detail below, with examples of embodiments shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this disclosure, and should not be construed as limiting this disclosure.

[0044] In the description of this disclosure, it should be understood that the terms “center,” “longitudinal,” “lateral,” “length,” “width,” “thickness,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “axial,” “radial,” and “circumferential” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this disclosure and simplifying the description, and are not intended to indicate or imply that the elements referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this disclosure.

[0045] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0046] In this disclosure, unless otherwise expressly specified and limited, terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0047] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0048] In one aspect of this disclosure, an electrode core 1000 is provided. According to an embodiment of this disclosure, referring to Figures 2-6, the electrode core 1000 includes a main body region 500 and a thinning region 600 connected to each other. The thinning region 600 is disposed on at least one side of the main body region 500 along a first direction (i.e., the X direction), where the first direction (i.e., the X direction) is the length direction or width direction of the electrode core 1000. The electrode core 1000 also includes a first adhesive layer 700 disposed on at least a portion of the surface of the thinning region. The first adhesive layer 700 includes a plurality of sub-adhesive layers 710, which are sequentially stacked along the thickness direction of the first adhesive layer 700 to fill the depressions in the thinning region 600.

[0049] The beneficial effects and principles of the electrode core proposed in this disclosure are explained in detail below:

[0050] This disclosure provides a novel electrode core 1000. Referring to Figures 3-6, a first adhesive layer 700 is formed on the surface of the thinned area 600. The first adhesive layer 700 includes multiple sub-adhesive layers 710, which are sequentially stacked along the thickness direction of the first adhesive layer 700 to fill the collapse of the thinned area 600. This allows the first adhesive layer 700 to perfectly adhere to the thinned area 600, achieving complete adhesion of the thinned area. During the HI-pot test, the thinned area is completely compressed, avoiding missed detections in the HI-pot test and improving the safety performance of the electrode core. Simultaneously, it avoids defects such as lithium plating and brown spots caused by thickness differences in the thinned area, preventing a drop in battery capacity and ensuring the cycle life and safety of the battery. Furthermore, by forming the first adhesive layer 700 on the surface of the thinned area, the adhesion between the thinned area and the separator is significantly improved, effectively preventing the electrode core from shifting, misaligning, and wrinkling during assembly. Furthermore, the core structure disclosed herein is simple, easy to implement, and low in cost.

[0051] According to some specific embodiments of this disclosure, the length of the sub-adhesive layer 710 decreases along the thickness direction of the first adhesive layer 700 away from the thinning area 600, thereby further ensuring that the first adhesive layer 700 can perfectly adhere to the thinning area 600, thus achieving the integrity of the adhesion of the thinning area.

[0052] According to some specific embodiments of this disclosure, the thicknesses of the plurality of sub-adhesive layers 710 are 0.05 mm to 0.1 mm, and for example, they can be 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm, etc., thereby further improving the adhesion between the first adhesive layer 700 and the electrode core thinning area.

[0053] According to the embodiments of this disclosure, referring to Figure 3, when the width of the thinned area 600 is short, a single unit adhesive layer can be used to achieve perfect adhesion between the first adhesive layer 700 and the thinned area 600.

[0054] According to the embodiments of this disclosure, referring to Figures 4-6, when the width of the thinning region 600 is relatively wide, it can be segmented according to the width of the collapse of the electrode core thinning region. Specifically, the first adhesive layer 700 of this disclosure includes at least two unit adhesive layers 720 arranged along a second direction (i.e., the Z direction). The second direction (i.e., the Z direction) is the thinning direction of the thinning region, and along the second direction (i.e., the Z direction) away from the main body region 500, the thickness of at least two unit adhesive layers 720 increases. That is, the first adhesive layer 700 of this disclosure can be divided into multiple unit adhesive layers 720 of different thicknesses. The thickness of each unit adhesive layer 720 increases along the thinning direction. The total number of unit adhesive layers 720 and the specific thickness, width, and length of each unit adhesive layer 720 can be specifically designed according to the shape of the thinning region, the degree of thinning, and the width of the electrode sheet to achieve perfect adhesion with the electrode core thinning region.

[0055] In the embodiments of this disclosure, during the production of positive and negative electrode sheets, due to limitations in the coating and rolling processes, the coating material near the edge of the foil may become thinner, forming a positive electrode sheet 100-1 with a thinned positive electrode sheet area and a negative electrode sheet 100-2 with a thinned negative electrode sheet area. Referring to Figure 1, the positive electrode sheet 100-1 with the thinned positive electrode sheet area, the separator 200, the negative electrode sheet 100-2 with the thinned negative electrode sheet area, and the separator 200 are sequentially stacked and wound to form an electrode core 1000. The edge region of the electrode core 1000 (i.e., the region where the thinned positive or negative electrode sheet area is located) is easily thinned under the action of external force; this thinned region is the thinned region 600 of the electrode core 1000. The width of the thinned region is the dimension along the first direction (i.e., the X direction).

[0056] According to further specific embodiments of this disclosure, along a second direction (i.e., the Z direction) away from the main body region 500, the thickness of at least two unit adhesive layers 720 increases gradually. That is, the thickness of a single unit adhesive layer 720 is equal, while the thicknesses of different unit adhesive layers 720 differ, and the thickness of at least two unit adhesive layers 720 increases gradually along the second direction (i.e., the Z direction) away from the main body region 500. Therefore, the total number of unit adhesive layers 720 and the specific thickness of each unit adhesive layer 720 can be specifically designed according to the shape of the thinned region and the degree of thinning, further ensuring that the first adhesive layer 700 achieves perfect adhesion to the electrode core thinning region. Furthermore, the first adhesive layer 700 with the above structure is easy to implement and has low cost.

[0057] In embodiments of this disclosure, the total number of unit adhesive layers 720 included in the first adhesive layer 700 is not particularly limited. For example, it may include two unit adhesive layers 720 (as shown in Figures 4 and 6) or three unit adhesive layers 720 (as shown in Figure 5). According to some specific embodiments of this disclosure, referring to Figures 4 and 6, the first adhesive layer 700 includes a first unit adhesive layer and a second unit adhesive layer arranged sequentially along the second direction (i.e., the Z direction). The first unit adhesive layer is disposed close to the main body region 500. The widths of the first unit adhesive layer and the second unit adhesive layer are (1 / 3 to 2 / 3)L, where L is the width of the thinned region. As an example, the width of the first unit adhesive layer can be 1 / 3L and the width of the second unit adhesive layer can be 2 / 3L, the width of the first unit adhesive layer can be 1 / 2L and the width of the second unit adhesive layer can be 1 / 2L, or the width of the first unit adhesive layer can be 2 / 3L and the width of the second unit adhesive layer can be 1 / 3L, etc. Furthermore, the thickness of the first unit adhesive layer is 0.05mm to 0.15mm (examples include 0.05mm, 0.08mm, 0.1mm, 0.12mm, 0.15mm, etc.), and the thickness of the second unit adhesive layer is 0.15mm to 0.3mm (examples include 0.15mm, 0.17mm, 0.2mm, 0.25mm, 0.27mm, 0.3mm, etc.). This further improves the adhesion between the first adhesive layer 700 and the electrode core thinning area.

[0058] According to some specific embodiments of this disclosure, referring to Figure 5, the first adhesive layer 700 includes a third unit adhesive layer, a fourth unit adhesive layer, and a fifth unit adhesive layer arranged sequentially along the second direction (i.e., the Z direction). The third unit adhesive layer is disposed close to the main body region 500. The widths of the third unit adhesive layer, the fourth unit adhesive layer, and the fifth unit adhesive layer are (1 / 4 to 1 / 2)L, where L is the width of the thinned region. For example, the width of the third unit adhesive layer can be 1 / 4L, the width of the fourth unit adhesive layer can be 1 / 4L, and the width of the fifth unit adhesive layer can be 1 / 2L; the width of the third unit adhesive layer can be 1 / 4L, the width of the fourth unit adhesive layer can be 1 / 2L, and the width of the fifth unit adhesive layer can be 1 / 4L; or the width of the third unit adhesive layer can be 1 / 3L, the width of the fourth unit adhesive layer can be 1 / 3L, and the width of the fifth unit adhesive layer can be 1 / 3L, etc. Furthermore, the thickness of the third unit adhesive layer is 0.05mm to 0.1mm (examples include 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, etc.), the thickness of the fourth unit adhesive layer is 0.1mm to 0.15mm (examples include 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, etc.), and the thickness of the fifth unit adhesive layer is 0.15mm to 0.3mm (examples include 0.15mm, 0.17mm, 0.2mm, 0.22mm, 0.25mm, 0.28mm, 0.3mm, etc.). This further improves the adhesion between the first adhesive layer 700 and the electrode core thinning area.

[0059] According to some specific embodiments of this disclosure, adjacent unit adhesive layers 720 can be spaced apart, with a spacing of no more than 2 mm. That is, the first adhesive layer 700 of the above structure is divided into at least two segments, each segment being formed by sequentially applying multiple layers of adhesive tape, further improving the adhesion between the first adhesive layer 700 and the electrode core thinning area.

[0060] According to some specific embodiments of this disclosure, adjacent unit adhesive layers 720 are connected to each other. That is, adjacent unit adhesive layers 720 can be formed by bonding with the same adhesive tape, and multiple sub-adhesive layers 710 can be formed by bonding with adhesive tapes of different widths in layers, which further improves the adhesion between the first adhesive layer 700 and the electrode core thinning area.

[0061] According to some specific embodiments of this disclosure, the sum of the thickness of the first adhesive layer 700 and the thickness of the corresponding thinned area in a third direction (i.e., the Y direction) is not greater than the thickness of the main body region 500. The third direction is the thickness direction of the electrode core, and the third direction is perpendicular to the first direction, thereby further ensuring the consistency of the thickness between the thinned area and the main body region 500.

[0062] In the embodiments of this disclosure, the material of the first adhesive layer 700 is not particularly limited. Conventional core tape materials can be used, as long as they can firmly adhere to the surface of the thinned area and have electrolyte resistance. As some preferred embodiments, the first adhesive layer 700 is made of polyurethane or polyimide. Both of these materials can firmly adhere to the surface of the thinned area and have electrolyte resistance, resulting in low cost. Furthermore, the bonding process is simple. For example, the first adhesive layer 700 can be formed by bonding tapes of different widths in layers, or by bonding tapes of different thicknesses in segments; any combination is possible.

[0063] According to some further embodiments of this disclosure, referring to Figure 6, the electrode core further includes: an electrode tab disposed at at least one end of the electrode core along a first direction (i.e., the X direction); and a second adhesive layer 800 disposed on at least a portion of the surface of the electrode tab near the thinning area, and the second adhesive layer 800 being connected to the first adhesive layer 700, thereby protecting the root of the electrode tab and preventing the electrode tab from bending or tearing.

[0064] Furthermore, the distance between the second adhesive layer 800 and the welding edge on the electrode tab is 3mm to 5mm, for example, it can be 3mm, 4mm, 5mm, etc., thereby effectively preventing poor melting of the tape due to welding heat radiation, while avoiding affecting the ultrasonic welding effect.

[0065] In the embodiments of this disclosure, the material of the second adhesive layer 800 is not particularly limited and can be a conventional electrode core tape material, as long as it can be firmly bonded to the surface of the electrode tab and has the property of being resistant to electrolyte. As some preferred embodiments, the material of the second adhesive layer 800 is polyurethane or polyimide. Both of these adhesive layers can be firmly bonded to the surface of the electrode tab and have the property of being resistant to electrolyte, and have low cost of use.

[0066] According to the embodiments of this disclosure, if the second adhesive layer 800 is not provided at the tab, the first adhesive layer 700 is provided on the surface of the diaphragm, and the distance between the first adhesive layer 700 and the edge of the diaphragm can be limited to 3mm to 5mm, thereby preventing the first adhesive layer 700 at the edge of the diaphragm from tearing, thereby achieving a step change in the thickness of the thinning area and achieving the same thickness as the main body.

[0067] As some preferred embodiments, the surface of the thinned area on both sides of the electrode core along the third direction is provided with a first adhesive layer 700.

[0068] Furthermore, the disclosed solution is applicable not only to electrode cores with narrow electrode widths and thinned sections only at the tab end, but also to electrode cores with wider electrode widths and thinned sections at the slit end. It is applicable not only to stacked electrode cores but also to wound electrode cores. The adhesive layer can be made of materials such as adhesive tape or swellable patches.

[0069] In this disclosure, referring to Figure 1, the battery 2000 includes a positive electrode 100-1, a negative electrode 100-2, and a separator 200. The separator 200 is disposed between the positive electrode 100-1 and the negative electrode 100-2. The positive electrode 100-1, separator 200, negative electrode 100-2, and separator 200 are sequentially stacked and wound to form an electrode core 1000, and the outermost two sides of the electrode core 1000 along a third direction (i.e., the Y direction) are the separators 200. The aforementioned positive electrode and / or negative electrode has an electrode thinning area. The edge region of the electrode core 1000 (i.e., the region where the electrode thinning area is located) is prone to forming a thinning area 600 under the action of external force. Therefore, this disclosure provides a first adhesive layer 700 on the surface of the thinning area 600 to fill the collapse of the thinning area 600.

[0070] In this disclosure, referring to Figure 1, the battery 1000 further includes a positive electrode tab 300-1, a negative electrode tab 300-2, a positive electrode post 400-1, and a negative electrode post 400-2. The positive electrode tab 300-1 is connected between the positive electrode post 400-1 and the positive current collector, and the negative electrode tab 300-2 is connected between the negative electrode post 400-2 and the negative current collector.

[0071] In a second aspect, this disclosure provides a battery. According to an embodiment of this disclosure, referring to Figure 1, the battery 2000 includes a housing 1500 and an electrode core 1000 as described above, the electrode core 1000 being disposed within the housing 1500. This improves the battery's safety performance, prevents a significant drop in battery capacity, and ensures the battery's cycle life.

[0072] In embodiments of this disclosure, the battery can be either a lithium-ion battery or a sodium-ion battery.

[0073] In a third aspect, this disclosure provides a battery pack. According to embodiments of this disclosure, an electrical device includes the battery described in the above embodiments. This improves the safety performance of the battery pack, prevents capacity drops, and ensures the cycle life of the battery pack.

[0074] In a fourth aspect, this disclosure provides an electrical appliance. According to an embodiment of this disclosure, the electrical appliance includes the battery described in the above embodiments. Therefore, the electrical appliance possesses all the advantages of a battery, which will not be elaborated further here.

[0075] Specifically, the aforementioned electrical equipment can include, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0076] It should be noted that the features and advantages described above for the battery also apply to this electrical device, and will not be repeated here.

[0077] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0078] Although embodiments of the present disclosure have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A type of electrode core, wherein, The electrode core includes a main body region (500) and a thinning region (600) connected to each other. The thinning region (600) is disposed on at least one side of the main body region (500) along a first direction, which is the length direction or the width direction of the electrode core. The electrode core further includes a first adhesive layer (700), which is disposed on at least a portion of the surface of the thinned area (600). The first adhesive layer (700) includes a plurality of sub-adhesive layers (710), which are sequentially stacked along the thickness direction of the first adhesive layer (700) to fill the collapse of the thinned area (600).

2. The electrode core according to claim 1, wherein, Along the thickness direction of the first adhesive layer (700) away from the thinning zone (600), the length of the sub-adhesive layer (710) decreases.

3. The electrode core according to claim 1 or 2, wherein, The thicknesses of the multiple sub-adhesive layers (710) are 0.05 mm to 0.1 mm, respectively.

4. The electrode core according to any one of claims 1 to 3, wherein, The first adhesive layer (700) includes a unit adhesive layer (720).

5. The electrode core according to any one of claims 1 to 3, wherein, The first adhesive layer (700) includes at least two unit adhesive layers (720), which are arranged sequentially along a second direction, which is the thinning direction of the thinning area (600), and the thickness of the at least two unit adhesive layers (720) increases along the second direction away from the main body area (500).

6. The electrode core according to claim 5, wherein, Along the second direction away from the main body region (500), the thickness gradient of at least two of the unit adhesive layers (720) increases.

7. The electrode core according to claim 5 or 6, wherein, The width of the thinning area (600) is L. The first adhesive layer (700) includes a first unit adhesive layer and a second unit adhesive layer arranged sequentially along the second direction. The first unit adhesive layer is disposed close to the main body area (500). The widths of the first unit adhesive layer and the second unit adhesive layer are (1 / 3 to 2 / 3)L, respectively.

8. The electrode core according to claim 7, wherein, The thickness of the first unit adhesive layer is 0.05mm to 0.15mm; And / or, the thickness of the second unit adhesive layer is 0.15mm to 0.3mm.

9. The electrode core according to claim 5, wherein, The width of the thinning area (600) is L. The first adhesive layer (700) includes a third unit adhesive layer, a fourth unit adhesive layer and a fifth unit adhesive layer arranged sequentially along the second direction. The third unit adhesive layer is disposed close to the main body area (500). The widths of the third unit adhesive layer, the fourth unit adhesive layer and the fifth unit adhesive layer are (1 / 4 to 1 / 2)L respectively.

10. The electrode core according to claim 9, wherein, The thickness of the third unit adhesive layer is 0.05mm to 0.1mm; And / or, the thickness of the fourth unit adhesive layer is 0.1mm to 0.15mm; And / or, the thickness of the fifth unit adhesive layer is 0.15mm to 0.3mm.

11. The electrode core according to any one of claims 5 to 10, wherein, The adjacent unit adhesive layers (720) are spaced apart, and the spacing is no more than 2 mm; Alternatively, adjacent unit adhesive layers (720) may be connected.

12. The electrode core according to any one of claims 1 to 11, wherein, The sum of the thickness of the first adhesive layer (700) and the thickness of the thinned area (600) corresponding to the first adhesive layer (700) in a third direction is not greater than the thickness of the main body area (500), where the third direction is the thickness direction of the electrode core and is perpendicular to the first direction.

13. The electrode core according to any one of claims 1 to 12, wherein, The first adhesive layer (700) is made of polyurethane or polyimide.

14. The electrode core according to any one of claims 1 to 13, wherein, The pole core also includes: A diaphragm (200) is provided on the surface of the diaphragm (200), and the distance between the first adhesive layer (700) and the edge of the diaphragm (200) is 3mm to 5mm.

15. The electrode core according to any one of claims 1 to 14, wherein, The pole core also includes: A tab, wherein the tab is disposed at at least one end of the electrode core along the first direction; A second adhesive layer (800) is disposed on at least a portion of the surface of the tab near the thinning area (600), and the second adhesive layer (800) is connected to the first adhesive layer (700).

16. The electrode core according to claim 15, wherein, The distance between the second adhesive layer (800) and the welding edge on the electrode tab is 3mm to 5mm.

17. The electrode core according to claim 15 or 16, wherein, The second adhesive layer (800) is made of polyurethane or polyimide.

18. A battery comprising a housing, wherein the battery further comprises an electrode core as described in any one of claims 1 to 17, the electrode core being disposed within the housing.

19. A battery pack, wherein, The battery pack includes the battery of claim 18.

20. An electrical appliance, wherein, Includes the battery of claim 18 or the battery pack of claim 19.

Images